Ukrainian President Volodymyr Zelenskyy spoke to members of Congress in a videoconference Saturday morning in which he asked for more lethal aid to fend off the invading Russian army and called for additional sanctions including a ban on Russian oil and a no-fly zone over Ukrainian airspace.

The airspace request came just as Russian President Vladimir Putin issued a threat to any country thinking about implementing a no-fly zone, saying Russia would regard it as active participation in the conflict. Western national security experts fear that such a move would amount to an American declaration of war against Russia, which holds the most nuclear weapons of any country in the world.

No-fly means that if Russian aircraft breached Ukrainian airspace, they could be shot down. President Joe Biden s administration has repeatedly rebuffed the suggestion, as has NATO.

So Zelenskyy asked for planes in the absence of airspace restrictions.

Senate Majority Leader Chuck Schumer (D-N.Y.) said the Ukrainian leader made a desperate plea for Eastern European countries to provide Russian-made planes to Ukraine.

These planes are very much needed, Schumer said, pledging to help facilitate their transfer.

Ukrainian fighters are less familiar with American-made planes, and negotiations with European countries to provide military aircraft to Ukraine have fallen apart . Sen. Rob Portman (R-Ohio) indicated that the U.S. could make a deal to compensate Eastern European nations in exchange for those countries supplying Ukraine with Soviet-style planes.

Zelenskyys top priority is to take back their skies, which are being used by Putin to wage war against cities and murder civilians, Sen. Ted Cruz (R-Texas) said in a statement.

More than 280 members of the House and Senate were present for the call with Zelenskyy, according to Sen. Chris Coons (D-Del.), a member of the Foreign Relations Committee.

The idea of sending more aid to Ukraine appears to have widespread support in both chambers.

Ukraine needs airpower urgently and America should send it. Zelenskys message is simple: Close the skies or give us planes, Sen. Ben Sasse (R-Neb.) said in a statement.

Lets be clear-eyed about our options: A No-Fly Zone means sending American pilots into combat against Russian jets and air defenses in a battle between nuclear powers that could spiral out of control quickly, Sasse said. But Americans should absolutely send Ukrainians planes, helicopters, and UAVs.

Coons said Zelenskyy underscored the urgent need for more military support and humanitarian aid from his Western partners.

Zelenskyy said that a ban on Russian oil imports could be even more powerful than the measures Western countries have taken to block Russian banks from using the SWIFT financial system, according to The New York Times . A bipartisan bill to block Russian oil and gas imports has growing support in the House and Senate , but the Biden administration has pushed back, due to the potential cost to Americans.

A Pentagon official said Friday that the vast majority of a $350 million aid package approved by the Biden administration last week at the start of the Russian invasion has arrived in Ukraine.

The Ukrainian capital of Kyiv is bracing itself for an even more vicious attack from a massive column of Russian forces slowly making its way to the city.

Citizens in other cities including Mariupol, which aid groups say is running out of food and medicine are increasingly desperate to leave. While Russian and Ukrainian authorities said they had reached a deal to form safe corridors for civilians to flee two areas of the country, Ukrainian officials accused the Russians of failing to hold up their end of the bargain, halting the evacuations.